They lived before the dinosaurs: scientists discovered the oldest creature on Earth
[ad_1]
Scientists have discovered the oldest living creature on Earth – a jellyfish-like organism called a ctenophor. The age of these creatures can reach 700 million years – they inhabited the planet long before the dinosaurs, which appeared only about 230 million years ago. The corresponding study was published by scientists from the University of California at Berkeley in the journal Nature, the BBC and Earth reported. Ctenophores are the closest relatives of primitive animals. Read also: Scientists have probably discovered the oldest evidence of a meteoroid falling to Earth Photo: MBARI Biologists have spent many years trying to find out what the oldest animals were. “There are 5 major genera that arose early in animal evolution and have survived to the present day: sponges (poriferans), ctenophores (comb-like coelacanths), placozoa (microscopic flat animals), coelacanths (such as anemones, jellyfish, and hydras), and bivalves ( chordates, molluscs, arthropods and various worms),” the study says. Gradually, scientists narrowed down the range of possible options to two groups: sponges and scalloped molluscs. Sponges spend their entire adult lives in one place, filtering food from seawater, while scallops swim deep in the oceans in search of food. Scientists have concluded that scallops have been around longer than sponges. The study not only allowed a new look at the chronology of animal evolution, but also refuted the long-held belief that the first animals were sea sponges. Sea sponges were considered to be the oldest, as their fossils date back to approximately 600 million years. In a new study, scientists used a new approach involving comparing the structure of chromosomes to get the final answer. Comb worms, or ctenophores, were the first lineage to branch off the animal tree. Sponges came next, followed by the diversification of all other animals, including the line leading to man. Although the researchers determined that the ctenophore lineage branched off earlier than the sponge lineage, both groups of animals continued to evolve from their common ancestor. However, evolutionary biologists believe that these groups still share features with the most ancient animals. “The most recent common ancestor of all animals probably lived 600 or 700 million years ago. It’s hard to say what those ungulates were like because they were soft-bodied and left no direct fossils. But we can use comparisons between living animals to find out about our common ancestors,” said Daniel Rochsar, a professor of molecular and cellular biology at the University of California, Berkeley. Darrin Schultz of the University of Vienna, who also participated in the study, added that the discovery “will lead to a better understanding of animal evolution.” It will be recalled that earlier scientists found the first creature in the world that does not need oxygen. Read also: What would modern dinosaurs be like if they did not die out?
[ad_2]
Original Source Link
